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Antimatter
Beginner
Every particle has an antiparticle with opposite charge.
Every particle has an antiparticle with the same mass and opposite charges (positron, antiproton). Matter and antimatter annihilate into energy.
PET scans detect positron annihilation gamma rays.
Mostly absent in the universe.
In more detail
Antimatter consists of particles with the same mass as ordinary particles but opposite charges and other quantum numbers. When matter meets antimatter, both annihilate and release energy.
Real-world uses
- Positron emission tomography uses antimatter for medical imaging.
- Particle physics experiments study antimatter to test symmetries.
- Medical PET scanners use positrons, the antiparticles of electrons, to image the body.
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Frequently asked questions
Is there antimatter in nature?
Yes, small amounts are produced in cosmic rays and lightning.
Why is there so little antimatter now?
The reason is a matter-antimatter asymmetry that is still under study.
What happens when matter meets antimatter?
They annihilate, releasing energy as photons, which is how positron emission imaging works.
Related topics in Particle Physics & Cosmology
Leptons · Quarks · Hadrons · Gauge bosons · Higgs boson · Standard Model